The evolution of the Blackriver concrete obstacles continues. Our new Kink Barrier is designed and tested by our team rider and Gripskin mastermind Manu Oberle. Get the real street feeling for your home as well. Size: 10 x 3.9 x 2.7 inch Attention: Fine hair cracks due to the slow drying process of concrete are normal and part of the realness factor of the material! The curb won´t break. Use wax to keep the surface of the concrete smooth, just like in skateboarding.